From owner-freebsd-current@FreeBSD.ORG Fri Oct 28 13:43:55 2005 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D9C0E16A41F; Fri, 28 Oct 2005 13:43:55 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id D099943D66; Fri, 28 Oct 2005 13:43:54 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 88B0746B3C; Fri, 28 Oct 2005 09:43:53 -0400 (EDT) Date: Fri, 28 Oct 2005 14:43:53 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: David Xu In-Reply-To: <436229CF.6040001@freebsd.org> Message-ID: <20051028144307.X53858@fledge.watson.org> References: <32412.1130505646@critter.freebsd.dk> <436229CF.6040001@freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Pertti Kosunen , Poul-Henning Kamp , current@freebsd.org, "Yuriy N. Shkandybin" Subject: Re: Timers and timing, was: MySQL Performance 6.0rc1 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Oct 2005 13:43:56 -0000 On Fri, 28 Oct 2005, David Xu wrote: > Poul-Henning Kamp wrote: > >>> On the other hand, a lower risk change might be to simply add a new >>> CLOCK_ type for lower resolution, and have a timer synchronize a >>> variable to the system clock once every 1/10 of a second. This avoids >>> having to muck with VM layout, etc. >> >> Is the CLOCK_* namespace ours to muck about with in the first place ? >> > I prefer this way, can you implement it? The global page idea is a > complex, someone can slowly work on it, there are many things can be > done, for example, fast syscall using sysenter/sysexit. I'm happy to take a stab at this. We still need someone to grab the context switch time keeping by the horns and Do Something, though. Robert N M Watson